Editing QEMM (section)

==QEMM Configurations==
QEMM provides up to 635K free conventional memory (RAM under 640K), far better than pure MS-DOS [[EMM386]], [[FreeDOS]] JEMM386, UMBPCI and many other memory manager programs.  QEMM maximum RAM is 635K free conventional memory with up to 256MB XMS/256MB EMS shared.

===MS-DOS 6.22, Windows 3.11/WFW 3.11===
MS-DOS 6.22 provides 619K free conventional memory and up to 64MB XMS/32MB EMS shared RAM.  Assuming unaltered MS-DOS 6.22, without 3rd party utilities, i.e. JEMM, UMBPCI, etc.  QEMM increases the available free conventional RAM to 635K with shared 256MB XMS/256MB EMS.

While using Windows 3.11 or Windows For Workgroups 3.11, QEMM provides additional free conventional memory for DOS Prompt running under Windows.  QEMM is well suited for Windows 3.x as has supported for it since QEMM v5.x as early as 1990.  As a result, QEMM 8.03 or QEMM 97 integrate very well with Windows 3.11/WFW 3.11.

===MS-DOS 7.10, Windows 95 OSR2/Windows 98 SE===
QEMM increases the available free conventional RAM for MS-DOS 7.10 and also for DOS Prompt under Windows 95 OSR2/Windows 98 SE.  However, QEMM maximum RAM is a shared 256MB XMS/256MB EMS, which is less than what DOS 7.10 and Windows 95/98 support without QEMM.  MS-DOS 7.10 provides 624K free conventional memory and up to 1GB XMS/32MB EMS; assuming unaltered MS-DOS, using HIMEM.SYS and EMM386.EXE without any 3rd party utilities.  Thus, QEMM is compatible with MS-DOS 7.10 and Windows 9x and provides slightly more free conventional RAM but it does lower the maximum RAM to 256MB XMS/256MB EMS.

=== Consequences of using or disabling EMS ===
[[Expanded memory|EMS]] memory normally uses a 64KB of UMB as the Page Frame, this reduces the total UMB available to DOS.  So some recommend turning off EMS, using the NOEMS switch, to increase the total UMB free by 64KB.  QEMM supports NOEMS switch, however, it is far better to provide EMS than saving the 64K Page Frame.<br />
<br />
QEMM takes advantage of EMS memory and usually will create more free RAM in the lower 1M address space than the 64KB required for EMS.  QEMM StealthROM, SqueezeFrame, and Stealth D*Space all require EMS to work by mapping ROM and data buffers into EMS, thus freeing more UMB's.<br />
<br />
QEMM's TechNote ''FRAME.TEC'' states: <small>''"Thus any advice to remove the page frame is penny-wise and pound-foolish.  Remember that the page frame is 64K of address space that can be used any program, at any time, to access effectively as much memory as it likes.  Some view the page frame as 64K of address space that could be used to hold up 64K of programs, but it is much more useful to consider the page frame as a place to access up to 32 megabytes of code and/or data for the programs that use it."''</small><ref>[http://www.chsoft.com/dv.html Quarterdeck Expanded Memory Manager QEMM 8.03 and QEMM 97] {{webarchive|url=https://web.archive.org/web/20060208042052/http://www.chsoft.com/dv.html |date=2006-02-08 }}, TechNote FRAME.TEC.</ref>

===Example: 635K Free, shared 256MB XMS/256MB EMS===
<syntaxhighlight lang="ini">
DOS=HIGH,UMB
device=C:\QEMM\dosdata.sys
device=C:\QEMM\qemm386.sys R:1 RAM UR=1M-256M ST:M I=b000-b7ff X=f000-ffff
device=C:\QEMM\dos-up.sys @C:\QEMM\dos-up.dat
shell=C:\QEMM\loadhi.com /R:2 C:\command.com C:\ /P /E:1024
</syntaxhighlight>
Note: If using VMware, then replace the qemm386.sys line with
<syntaxhighlight lang="ini">
device=C:\QEMM\qemm386.sys R:1 RAM UR=1M-256M X=e800-e900
</syntaxhighlight>

===Skipping QEMM386 while booting===
Hold '''ALT''' key during boot and qemm386.sys will not load but prompt to hit '''Esc''' to skip loading.

Alternatively, hold '''F5''' so DOS skips loading all of config.sys + autoexec.bat or hold '''F8''' so DOS prompt Y/N to confirm each line in config.sys and autoexec.bat; allowing you to skip loading qemm386.sys, dos-up, dosdata, etc.

May help while testing new configuration that lead to system lockups.  Holding ALT or pressing F5/F8 during boot might be the saving touch!